Goroh Saitoh

Estimating Dielectric Anisotropy of Liquid Crystal Compounds

Abstract An applications of the molecular orbital (MO) calculation and Maeir-Meier theory to liquid crystal compounds are investigated for estimating dielectric anisotropy (δϵ). The method involves calculating the parameters on MO calculation and substituting these values into Maeir-Meier theory. These calculations are repeated until the calculated δϵ saturates. The estimated δϵ agree closely with those obtained experimentally for liquid crystal compounds with various skeletons and polarized groups.

New ferroelectric liquid crystals with a trifluoromethyl group

Abstract New chiral dopants, possessing a trifluoromethyl group, have been synthesized. These dopants have different polar groups, located between the chiral centre and the diphenylacetylene core. The polar part is chosen from ester, methylene ether and ether linkages. Each new chiral dopant was mixed with a non-chiral liquid crystal mixture or a ferroelectric liquid crystal mixture, and their transition temperatures and electrooptic properties measured. The largest spontaneous polarization, 4·1 nC cm−2, was obtained at 25°C for the ferroelectric liquid crystal mixture in which the dopant, with a methylene ether linkage, was incorporated. Molecular orbital calculations (MNDO method) for the dopants show that the calculated dipole moments are correlated with the measured spontaneous polarization, and the calculated results explain the experimental results quite well. In addition, it has been found that the conformation of the chiral part is an important factor which affects the magnitude of spontaneous pol...

22.2: RGB-Stacked Holographic Polymer Dispersed Liquid Crystal Device for Color Reflective Display

In stacking holographic PDLC devices, the parallax in the stack and the viewing angle should be considered. Based on a thin glass substrate (thickness = 0.1mm) assembly technique and an optical setup with a lenticular-lens array, RGB-stacked HPDLC devices with a low parallax and a large viewing angle (>15 degrees) have been developed.